Substrate transfer apparatus, substrate processing apparatus including the same, and substrate misalignment compensation method

Abstract

A substrate misalignment compensation method includes obtaining first coordinates for an amount of movement of a substrate transfer apparatus and second coordinates measured by a plurality of sensors installed on the substrate transfer apparatus while moving the substrate transfer apparatus in one direction, calculating a calibration value of the substrate transfer apparatus by using an equation of a circle for the first coordinates and an equation of a line for the second coordinates, and calculating the center of a circle for a substrate based on the calibration value of the substrate transfer apparatus and compensating for misalignment of the substrate by using the center of the circle.

What is claimed is: 
     
       1. A substrate misalignment compensation method of a substrate transfer apparatus for transferring a substrate comprising:
 obtaining first coordinates of the substrate transfer apparatus and second coordinates measured by a plurality of sensors installed on the substrate transfer apparatus while moving the substrate transfer apparatus in one direction; 
 calculating a calibration value of the substrate transfer apparatus by using an equation of a circle centered at the first coordinates and an equation of a line passing through the second coordinates; and 
 calculating the center of a circle to determine a center of the substrate based on the calibration value of the substrate transfer apparatus and compensating for misalignment of the substrate by using the center of the circle. 
 
     
     
       2. The substrate misalignment compensation method of  claim 1 , wherein the calculating of the calibration value of the substrate transfer apparatus includes:
 calculating coordinates at which the equation of the circle and the equation of the line meet; 
 calculating a moving distance of the plurality of sensors by using the coordinates at which the equation of the circle and the equation of the line meet; and 
 calculating the calibration value of the substrate transfer apparatus by using the moving distance of the plurality of sensors. 
 
     
     
       3. The substrate misalignment compensation method of  claim 2 , wherein the calculating of the calibration value of the substrate transfer apparatus by using the moving distance of the plurality of sensors includes:
 calculating the calibration value of the substrate transfer apparatus by adding the moving distance of the plurality of sensors and zero set values of the plurality of sensors. 
 
     
     
       4. The substrate misalignment compensation method of  claim 2 , wherein the equation of the circle is (x−a) 2 +(y−b) 2 =r 2 ,
 wherein the equation of the line is x=(x1/y1)y, and 
 wherein “a” and “b” are central coordinates of the substrate after the substrate transfer apparatus is moved in the one direction, “r” is a radius of the substrate, and “x1” and “y1” are the second coordinates for a position of the sensor. 
 
     
     
       5. The substrate misalignment compensation method of  claim 4 , wherein the calculating of the coordinates at which the equation of the circle and the equation of the line meet includes:
 substituting the equation of the line into the equation of the circle, resulting in Ay 2 + By+C=0, and calculating the coordinates at which the equation of the circle and the equation of the line meet, by using 
 
       
         
           
             
               
                 y 
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                       B 
                     
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                           B 
                           2 
                         
                         - 
                         
                           4 
                           ⁢ 
                           
                               
                           
                           ⁢ 
                           AC 
                         
                       
                     
                   
                   
                     2 
                     ⁢ 
                     A 
                   
                 
               
               , 
             
           
         
       
       x=(x1/y1)y. 
     
     
       6. The substrate misalignment compensation method of  claim 2 , wherein the compensating of the misalignment of the substrate includes:
 calculating compensated position values of the plurality of sensors based on the moving distance of the plurality of sensors; 
 calculating the center of the circle to determine the center of the substrate by using at least three of the compensated position values of the plurality of sensors; and 
 comparing the calculated center of the circle and a preset value to compensate for the misalignment of the substrate. 
 
     
     
       7. The substrate misalignment compensation method of  claim 2 , wherein the calculating of the moving distance of the plurality of sensors includes:
 calculating the moving distance of the plurality of sensors by using √{square root over ((x−x1) 2 +(y−y1) 2 )}, wherein “x” and “y” are calculated coordinates at which the equation of the circle and the equation of the line meet, and “x1” and “y1” are the second coordinates for a position of the sensor. 
 
     
     
       8. The substrate misalignment compensation method of  claim 1 , wherein the obtaining of the first coordinates and the second coordinates includes:
 repeatedly performing a process of obtaining the first coordinates and the second coordinates after moving the substrate transfer apparatus by a preset distance in the one direction. 
 
     
     
       9. The substrate misalignment compensation method of  claim 8 , wherein the preset distance is 0.1 mm. 
     
     
       10. The substrate misalignment compensation method of  claim 1 , wherein the plurality of sensors are installed on the substrate transfer apparatus so as to be spaced apart from each other by a predetermined gap along a circumferential direction of the substrate. 
     
     
       11. A substrate transfer apparatus for transferring a substrate, comprising:
 a support part configured to support the substrate; 
 a driving unit configured to move the support part; and 
 a control unit configured to control a movement of the driving unit, 
 wherein the control unit includes: 
 a sensor module configured to obtain first coordinates of the substrate transfer apparatus and second coordinates measured by a plurality of sensors installed on the substrate transfer apparatus while moving the substrate transfer apparatus in one direction; 
 a calculation device configured to calculate a calibration value of the substrate transfer apparatus by using an equation of a circle centered at the first coordinates and an equation passing through a line for the second coordinates; and 
 a compensation device configured to calculate the center of a circle to determine a center of the substrate based on the calibration value of the substrate transfer apparatus and compensate for misalignment of the substrate by using the center of the circle. 
 
     
     
       12. The substrate transfer apparatus of  claim 11 , wherein the calculation device calculates coordinates at which the equation of the circle and the equation of the line meet, calculates a moving distance of the plurality of sensors by using the coordinates at which the equation of the circle and the equation of the line meet, and calculates the calibration value of the substrate transfer apparatus by using the moving distance of the plurality of sensors. 
     
     
       13. The substrate transfer apparatus of  claim 12 , wherein the calculation device calculates the calibration value of the substrate transfer apparatus by adding the moving distance of the plurality of sensors and zero set values of the plurality of sensors. 
     
     
       14. The substrate transfer apparatus of  claim 12 , wherein the equation of the circle is (x−a) 2 +(y−b) 2 =r 2 ,
 wherein the equation of the line is x=(x1/y1)y, and 
 wherein “a” and “b” are central coordinates of the substrate after the substrate transfer apparatus is moved in the one direction, “r” is a radius of the substrate, and “x1” and “y1” are coordinates for a position of the sensor. 
 
     
     
       15. The substrate transfer apparatus of  claim 14 , wherein the calculation device substitutes the equation of the line into the equation of the circle, resulting in Ay 2 + By+C=0, and calculates the coordinates at which the equation of the circle and the equation of the line meet, by using 
       
         
           
             
               
                 y 
                 = 
                 
                   
                     
                       - 
                       B 
                     
                     ± 
                     
                       
                         
                           B 
                           2 
                         
                         - 
                         
                           4 
                           ⁢ 
                           
                               
                           
                           ⁢ 
                           AC 
                         
                       
                     
                   
                   
                     2 
                     ⁢ 
                     A 
                   
                 
               
               , 
             
           
         
       
       x=(x1/y1)y. 
     
     
       16. The substrate transfer apparatus of  claim 12 , wherein the compensation device calculates compensated position values of the plurality of sensors based on the moving distance of the plurality of sensors, calculates the center of the circle for the substrate by using at least three of the compensated position values of the plurality of sensors, and compares the calculated center of the circle and a preset value to compensate for the misalignment of the substrate. 
     
     
       17. The substrate transfer apparatus of  claim 12 , wherein the calculation device calculates the moving distance of the plurality of sensors by using √{square root over ((x−x1) 2 +(y−y1) 2 )}, wherein “x” and “y” are calculated coordinates at which the equation of the circle and the equation of the line meet, and “x1” and “y1” are coordinates for a position of the sensor. 
     
     
       18. The substrate transfer apparatus of  claim 11 , wherein the control unit repeatedly performs a process of obtaining the first coordinates and the second coordinates after moving the substrate transfer apparatus by a preset distance in the one direction. 
     
     
       19. The substrate transfer apparatus of  claim 18 , wherein the preset distance is 0.1 mm. 
     
     
       20. The substrate transfer apparatus of  claim 11 , wherein the plurality of sensors are installed on the substrate transfer apparatus so as to be spaced apart from each other by a predetermined gap along a circumferential direction of the substrate. 
     
     
       21. An apparatus for processing a substrate, the apparatus comprising:
 a processing module including a process chamber in which a process is performed on the substrate; 
 a load port on which a carrier having the substrate received therein is placed; and 
 a substrate transfer apparatus configured to transfer the substrate, 
 wherein the substrate transfer apparatus includes: 
 a support part configured to support the substrate; 
 a driving unit configured to move the support part; and 
 a control unit configured to control a movement of the driving unit, and 
 wherein the control unit includes: 
 a sensor module configured to obtain first coordinates of the substrate transfer apparatus and second coordinates measured by a plurality of sensors installed on the substrate transfer apparatus while moving the substrate transfer apparatus in one direction; 
 a calculation device configured to calculate a calibration value of the substrate transfer apparatus by using an equation of a circle centered at the first coordinates and an equation of a line passing through the second coordinates; and 
 a compensation device configured to calculate the center of a circle to determine a center of the substrate based on the calibration value of the substrate transfer apparatus and compensate for misalignment of the substrate by using the center of the circle. 
 
     
     
       22. A computer readable recording medium having a program recorded therein for executing the substrate misalignment compensation method according to  claim 1  by a computer.